Ice cube making apparatus



Nov. 8, 1960 l D. F. swANsoN 2,959,026

. ICE CUBE MAKING APPARATUS Filed March 7, 1955 2 Sheets-Sheet 2 2 INVENTOR Dona/a Swanson ATTORNEY United States Patent ICE CUBE MAKING APPARATUS Donald F. Swanson, St. Paul, Minn., assignor, by mesne assignments, to Whirlpool Corporation, a corporation of Delaware Filed Mar. 7, 1955, Ser. No. 492,612

8 Claims. (Cl. 62-138) This invention relates to an improvement in ice cube making apparatus and deals particularly with a means of controlling the thickness of the ice cubes and of controlling the ice cube making apparatus.

In a previous application of Russell W. Ayres and Donald F. Swanson, Serial No. 306,096, an ice cube maker was disclosed which freezes a slab of ice on an inclined plate until the slab has built up to a desired thickness and which then releases the slab of ice so that it will slide onto a series of heated wires which cut the slab of ice into individual cubes. This apparatus functions eiectively for its prescribed purpose. However, one diiculty is involved. In the previous apparatus 'a control was operated when the ice moved onto the heated wires which served, after a period of time, to recycle the apparatus and to start the formation of a new slab of ice on the inclined refrigerated plate. Through the use of this arrangement a certain amount of time was wasted between cycles, thereby limiting the production of ice cubes a corresponding amount.

In the previous structure a thermostatic switch was suspended at a desired distance from the refrigerated plate and the control was operated when the ice built up suiiiciently either to contact this thermostatic unit or so that the cooled water flowing over the ice contacted the thermostatic unit. This thermostatic unit controls the operation of the pump used to force water over the refrigerator plate and some time was required to elevate the temperature of the thermostatic unit after the ice had moved from the inclined plate so that the cycle would be repeated. It is the object of the present invention to eliminate this waiting period.

A feature of the present invention resides in the provision of a member supported above the inclined plate and which is engageable with ice upon the inclined plate. This member is elevated when ice builds up to a predetermined thickness and operates a suitable switch to discontinue the ow of Water and to operate means for releasing the slab of ice from the plate.

A feature of the present -invention resides in the provision of a switch mounted above `a refrigerated plate and actuated by a member engageable with the upper surface of a slab of ice on the inclined plate. When the thickness of the ice reaches a predetermined limit the switch is actuated to control the ice slab removal. As soon as the slab of ice has passed from beneath the switch actuating means lthe switch is again operated to initiate another freezing cycle.

A further feature of the present invention resides in the provision of a member supported above an inclined freezing plate and which is movable into and out of contact with ice frozen upon the plate. This movable member is operable at predetermined intervals and is moved against the surface of the ice slab when the slab becomes suii'iciently thick. Movement of the movable member against the ice functions to operate suitable switch mechanism to control the freezing cycle. As a result the mov- 2,959,026 Patented Nov. 8, 1960 ICC Y able member is intermittently engaged with the ice surface member which is designed to contact the surface of the f ice slab.

Figure 3 is a diagrammatic view showing the refrigeration system of the ice cube machine and showing the electrical circuits controlling the various parts thereof.

Figure 4 is an elevational View of a modified form of construction of ice slab engaging member.

IIn general the ice cube making machine is similar to Vthat disclosed in the co-pending application above referred to. The machine is shown as including a well-type cabinet 10 having anice cube receiving well 11 into which the ice cubes drop by gravity. The cabinet 10 includes a compressor chamber 12 and the upper portion of the cabinet extends both across the Well 11 and the compressor compartment 12 to provide an ice cube forming compartment 13 which is -above the level of the well 11 and the chamber 12 in the particular arrangement illustrated.

The cabinet 10 normally includes an outer liner 14 and well liner 15 which connects with the liner 16 of the ice cube making chamber 13. The compartment 12 encloses refrigeration apparatus including a compressor or blower 17 which is driven by a motor such as 19. The compartment 12 may also include a condenser 18 shown in Figure 3 and other parts of the refrigeration mechanism.

A pump 20 is supported at the lower end of the ice cube forming chamber 13 and is driven by'a motor 21 depending into the compartment 12. The pump 20 operates through a suitable outlet 22 or plurality of outlets to deliver water to a manifold 23 extending across the upper end of a refrigerated plate 24. A trough 25 is provided as the lower end of the plate 24 and water collected in the trough 25 is transmitted by a conduit 26 to the pump 20.

Water is normally contained in a receptacle 27 encircling the pump 20 and is forced by the pump through the conduit 22 and the manifold 23 to flow over the plate 24. This water is then returned to the receptacle 27 and is again pumped over the plate 24. A syphoning tube 29 is connected to the receptacle 27 to empty the water at the termination of each cycle. However, the water does continue to circulate through a freezing cycle. The water level in the receptacle 27 is controlled by a float 30 which controls a water inlet valve 31 to maintain a proper water level in this receptacle.

A frame' 31 is supported beneath the level of the lower end of the plate 24 and this frame supports a series of resistance wires 32 extending longitudinally with respect to the plate 24 and a second set of resistance wires 33 which are supported transversely of the plate 24. When a slab of ice rests upon the wires 32, these wires cut the ice into a series of elongated strips. These strips are cut into cubes by the transverse wires 33.

As is indicated in Figure 3 of the drawings, the compressor 17 forces refrigerant through a conduit 34 into The refrigerant then ows through the plate cooling conduit 37 which, in practice, may be built into the plate.

3 The coil 37 leads to the return line 39 leading to the compressor 17.

A hot refrigerant gas line 40 leads from the condenser 18 through. a.solenoid valve 41 to a hot vgas line 42 which encircles the marginal edge of the refrigerated' plate 24. When the valve 41 is open, hot gas may ow from the condenser 18 through. the hot gas line 42 which connects with the coil 37 at 43 in a manner to bypass the valve 36; Thus, when the valve is open, the hot refrigerant gas is circulated through therefrigerating plate and particularly along the peripheral edges thereof so as to loosen the slab of ice and to permit it to slide by gravity onto the wires 32.

The foregoing construction was described in the application previously referred to. The improvement in the present application is indicated in the structure shown in Figure 2.

As is indicated` in Figure 2, a motor 44 is hingedly supported along a transverse pivot 45 to a bracket 46 mounted upon the-frarne 47 surrounding the freezing plate 24. The motor 44 operates through suitable gearing, not illustrated inthe drawings, to rotate a vertical shaft 49 at a relatively slow speed. The shaft 49 is provided with a cylindrical cam 50 having an inclined lower extremity 51. The cam 50 may be of any desired diameter to provide the necessary movement of the motor 44 as will be described.

The bracket 46 is vequipped with a switch 52 which includes a plunger 53 actuated by a suitable blade 54 attached to the motor. The particular type of switch shown is merely for the purpose of illustration and any suitable switch structure can be employed.

The switch 52 is so arranged that when the slab of ice 55 is relatively thin or is absent entirely, the blade 54 will rest upon the plunger S3 and close a circuit which will be later described and which operates the pump and the solenoid 41. The inclined lower end of the cam 50 is normally out of contact with the ice slab 55 throughout most of its rotation. However, upon suicient rotation of the cam 50, the low point 56 of the cam will engage the inclined surface of the ice slab and will raise the motor 44 about its pivot axis 45. Thus, when the ice builds up sufficiently, the cam will raise the motor to lift the blade 54 out of engagement with the plunger 53 permitting this plunger to actuate the switch 52 in an opposite position.

The motor 44 is connected to rotate continuously during the operation of the apparatus and to rotate the low point 56 of the cam 50 very slowly. Obviously the low point of the cam will first engage the surface of the ice when the low point is directed toward the upper end of the freezing plate as is indicated in Figure 2. During the remainder of its rotation the low point of the cam Will be free of the slab surface, thereby, not interferring with the freezing of the ice.

The rotation of the cam 50 will continue until the surface of the slab 55 is suiciently high to raise the cam and the motor 44 on which it is mounted to a point where the switch 52 is actuated. Previous to this time the low point of the cam will be rotated into the position shown in Figure 2 at timed intervals which may be twenty seconds, as an example, or may be a greater or lesser time, as desired.

With reference now to Figure 3 of the drawings, it will be noted that the line wiresV 57 and 59 supply current and that the line wire 57 is connected to a common wire 60, leading to one terminal 61 of the compressor motor 19 and leading to one terminal 62 of a transformer 63 which supplies low voltage current to the wires 32 and 33. The line wire 57 is also connected to one terminal 64 of the motor 44 and to a common contact arm 65 of a single pole double throw switch 52. The line wire 59 is connected through a main switch 66 and a thermostatic switch 67 to the second terminal 69 of the motor 44. The line wire is also connected through the same switches 66 and 67 to the second terminal 70 of the compressor motor 19 and to the second terminal 71 of the transformer 63. The line wire 59 `is yalso connected through the switches 66 and 67 to a terminal 72 of the pump motor 21 and to one terminal 73 of the solenoid switch 41. The second terminal 74 of the solenoid switch 41 is connected by a conductor 75 to a normally open contact 76 of the switch 52, while the second terminal 77 of the pump motor 21 is connected to the-normally closed terminal 79 of the switch 52.

The thermostatic switch 67 is controlled by the level of ice in the well 15 and acts to cut olf the operating mechanism when the well is lled with ice cubes. Otherwise, this thermostatic switch remains closed to permit continuous operation of the motor 44 and the compressor 19.

The switch 52 normally closes a circuit to the pump motor 21. However, when the slab of ice reaches a predetermined thickness, the motor 44 pivots upwardly operating the switch 52 in a manner to open `the contactV with the pump motor 21 to stop the `flow of water. Simultaneously a circuit is closed to the solenoid valve'41 to open this valve and to permit the flow of refrigerant gas into the coil. This hot refrigerant gas heats the freezing plate so that the slab of ice is freed-therefrom. When the slab slides from the freezing plate the cam 50 and the motor 44 pivot downwardly, thereby reversing the'circuit and starting the pump motor 21 in operation and closing the circuit to the solenoid Valve 41.

In Figure 4 ofthe drawings a modified form of construction is illustrated which is very similar to that previously described. In the arrangement shown in Figure 4 the bracket 46 supports'a motor 80 having a Vtransverse driven shaft 81. A cam 82 is mounted upon the shaft 81 and rotates in unison therewith. The cam 82 is provided with one or more lobes 83 which are sequentially rotated toward the ice slab 55. When the slab of ice is of sufficient thickness a lobe 83 engages the upper surface of the ice slab and swings the motor upwardly, thereby actuating the switch 52.

In accordance with the patent statutes, I have described the principles of construction and operation of my ice cube making apparatus, and vwhile I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

l. In combination in an ice cube making apparatus and controls therefor, an inclined plate, means for refrigerating said plate, means for circulating water over said plate, means for interrupting 4the refrigerating of said' plate and the circulation of said water, and a contro-l for .into and out of ice engaging position, said ice engaging member engaging the ice in said ice engaging position to raise said ice engaging member when said ice reaches a predetermined thickness, and means actuated by engagement of said yice engaging member With the ice to actuate said interrupting means into an interrupting position.

2. The construction described in claim l and in Which said interrupting means comprises a switch and including a circuit which includes a source of power, said switch, and said circulating means.

3. In combination, an ice cube making apparatus including an inclined surface on which ice may be formed, said surface being in ,contact with Water to be frozen,

the ice thereon Without substantially melting the same, a control for controlling said interrupting means, said control including la movably mounted member supported:

above said surface and including a projection movable towand and away from said surface upon movement of said movable member and engageable with the ice when the ice reaches a predetermined thickness on said inclined surf-ace, and means for moving said movably mounted member in cycles to move said projection thereof to a definite minimum distance above said sunface, engagement of said projection of said movably mounted member with the upper side of lthe ice elevating said movably mounted mem-ber and actuating said interrupting means into an interrupting position.

4. The construction described in claim 3 and in which said movable member is rotatable.

5. The construction described in claim 3 and in which the water is circulated over said inclined surface.

6. Ice cube making apparatus comprising an inclined plate, means adjacent the upper end of said plate for passing water over said plate, means `for refrigerating said plate to gradually build up a layer of ice thereon from said water, switch means fo-r controlling said refrigerating means includ-ing a ypair of switch contacts ybiased to open position and a vertically reciprocal plunger for actuating said contacts into a closed position, a generally horizontal member pivotally supported at one end and having its free end normally engaging said plunger to close said contacts, motor means mounted on said pivotally supported mem-ber for movement therewith, probe means rotatably supported by said pivotally supported member and connected to said motor means for rotation thereby, said probe including a projection movable toward and away from said plate upon rotation of said probe, said projection being movable into an angular position spaced a preferred minimum distance above said inclined plate, whereby when said layer of ice has increased in thickness so as to be engagcable with said projection, said pivotally supported member will be pivoted about its one end to raise its free end suiciently to permit separation of saidcontacts.

7. The construction described in claim 6 in which said probe means includes a cam rotatable about a vertical axis, said projection :being vformed on said cam.

8. The construction described in claim 6 in which said probe means includes a cam rotatable about a horizontal axis, said projection being formed on said cam.

References Cited in the file of this patent UNITED STATES PATENTS 2,007,409 Schweitzer July 9, 1935 2,650,479 Kattis Sept. 1, 1953 2,685,952 Hamlin Aug. 10, 1954 2,747,375 Pichler May 29, 1956 FOREIGN PATENTS 486,075 Great Britain May 30, 1938 OTHER REFERENCES Air Conditioning and Refrigeration News, February 25, 1952, page 1l. 

